I have been there. The last semester I enrolled at was fall 2010, about 6 months ago. I did not find any value in pursuing a degree that contained subjects I had no interest in whatsoever (my major was Information and communication technology), I chose not to enroll during the spring semester in favor of attaining professional certifications (Cisco CCIE) as I had taken an interest in them and attained "lower level certs" before that. (The CCIE is considered the holy grail of networking.

Lately however, I have fallen in love with programming and software development, and I have been studying with a passion. This has led me to conclude that throughout the length of my career, I will be involved with different technologies and perhaps even disciplines. Technology is full of uncertainty, you do not know where you will be in 2 years (let alone 5), what if you get a referral for that dream job but it requires a degree? Or if you decide to build a startup and it tanks--you would have to consider employment to regain at least some of the money you have lost.

There are countless other scenarios in which you may regret not having completed your degree. However, the most important thing to consider is that once you quit, you would lose out on opportunities--what they exactly are, you will never find out.

EDIT: This is in response to your edit indicating that you are not dropping out of school. That is good. But if anything, you should drop the music major.